1. Field of the Invention
The present invention relates to an animal tooth cleaning device that is adapted to be gripped in the mouth of an animal, e.g., a dog, such that the animal's teeth are automatically cleaned while the animal's teeth are in rubbing contact with the device.
2. Discussion of the Related Art
Maintaining good dental hygiene is just as important for pet animals, such as dogs and cats, as it is for their human owners. Dogs and cats do not get cavities the way humans do. Periodontal, or gum disease, however, is a common problem for dogs and cats due to the buildup of tartar or calculus on the teeth. As many as 80% of dogs and cats over three years of age may suffer from some form of it. Infected gums can easily transmit bacteria to the blood stream, causing serious illness.
Pet owners should be aware of the serious problems created when their pet's teeth are neglected. Gum disease or an infected tooth can affect the overall health of the animal and also reduce the animal's life expectancy. Additionally, a dental infection can lead to liver, heart, and kidney damage.
Many animals put up with dental pain in silence. It is possible that an animal with an infected tooth might exhibit only a slight discoloration in the mouth. Some pets may stop drinking cold water or eating harder foods. It is possible that an animal's reaction to a dental problem can be so subtle that the mouth disease may go unnoticed until it becomes a serious problem.
The field of animal dentistry is relatively new. More veterinarians are becoming skilled in dental procedures. As an alternative to pulling teeth, root canals, orthodontics and tooth reconstruction are being performed. As with humans, however, maintaining dental health requires regular maintenance, i.e., a daily routine of brushing.
Most pet owners would understand the difficulties involved in having to brush their pet's teeth everyday. Many animals just won't tolerate the experience. If this daily brushing is attempted, but is unsuccessful, an owner may be tempted to discontinue the practice, thereby endangering their pet's health.
There are known devices on the market which hold themselves out as helping to maintain the dental health of a dog or a cat. These items include Milk-Bone.RTM. dog biscuits, rope chews, as well as chew toys made from cow's hooves.
The plaque that builds up on an animal's teeth, causing gum disease, must be removed from at, or under, the gum-line. The aforementioned items, however, do not remove plaque below the gum-line. The knotted nylon "bones" and rawhide, while providing good chewing surfaces and removing plaque from the surface of teeth, do not go below the gum-line and may cause intestinal obstructions if swallowed. Cow hooves, although a popular chew treat, can become wedged between the dog's teeth, leading to serious dental problems. As an alternative, hard rubber and softer nylon-type chew toys are proposed but, once again, these do not clean below the gum-line.
Another disadvantage of rope bones for cleaning teeth is that dogs just tend to tear them with their front teeth instead of really chewing. This fails to clean the back molars. There is also a risk that the dog will tear apart the rope bone and thus choke on large pieces of rope.
U.S. Pat. No. 5,126,137, issued to W. S. Lambert on Jun. 30, 1992, (hereinafter "Lambert '137) shows a device adapted to be gripped by an animal's tooth to exert a tooth cleaning action. The device comprises an open-celled foam body encased in a sheath, or covering, formed of an open weave gauze material. The gauze material is preferably a tough, high strength material, such as dacron, nylon or Kevlar.TM., in thread form, whereby the animal's teeth are not likely to break the gauze threads when the animal exerts a biting action on the device. The device preferably has a dog bone shape or a hot dog shape.
The foam body of Lambert'137 is impregnated with various food substances or materials in order to attract the animal (dog or cat) to the device. Lambert mentions water-soluble beef flavoring, catnip and mild dental abrasives, as materials that can be impregnated into the foam body.
When the device is attacked by the dog, or other animal, the animal's teeth penetrate the gauze sheath material so that the gauze threads have a rubbing action on the side surfaces of the teeth. This rubbing action produces a tooth cleaning effect. It, however, does not clean below the gum.
One potential problem with the device of Lambert is that the animal's teeth can potentially become stuck in the threads of the gauze covering, such that the animal is prevented from letting go of the device; the device could conceivably stick to the animal's mouth even against the efforts to let go of the device. If the pore openings in the gauze are sufficiently small that the gauze threads rub on the animal's teeth, then presumably (in some cases) the threads can grip the side surfaces of the teeth so that the threads become stuck in the tooth spaces.
Another problem with Lambert's '137 device is that only limited quantities of attractant materials (catnip, toothpaste, etc.) can be impregnated into the foam body. After a comparatively few biting actions by the animal essentially all of the attractant material will be extruded out of the foam body. It is believed that the device of Lambert '137 would have a relatively short service life, i.e., a relatively few bite cycles, before depletion of the attractant material to an ineffective level.
Another problem with the device of Lambert '137 is that the fluid impregnated into the sponge is likely to squirt out of the sponge at undesired locations. Movement of the animal tooth into the sponge at one point is likely to depress other areas of the sponge, thereby causing uncontrolled squirting of the fluid in various different directions.
Thus, what is needed is an apparatus that will remove plaque from an animal's teeth, not only at the surface of the teeth, but also below the gum-line so as to reduce the occurrence of gum disease. Such a device should be one that the animal can implement itself through a normal action such as, for example, chewing.